Android device manager Update with update 1.8.5

I recently tried android device manager for the first time since I installed 1.8.5 I don’t know if it is related but ADM no longer works, has anyone else noted a problem?

The symptoms are that ADM can locate the FP1 but if i use ADM to remote lock the device then the FP1 seems to lock but I can never get a keypad to unlock it, the phone appears to have hung with a lock sreen, Worryingly if I reboot a few times, 2 or 3 normally, I get access to the phone, ie the lock screen from ADM gets forgotten.